Noise absorbing element in block form

ABSTRACT

A noise absorbing element capable of being vertically stacked and/or attached to vertical members includes a tube which is rectangular in cross-section which forms the front, back and side walls of the element. One or more partitions and/or spacing elements are located inside the tube and divide the interior thereof into at least a front cell and a rear cell. The front cell is closed at the bottom and is filled with a sound absorbing material such as glass or rock wool. For vertically stacking, the upper or lower end of the tube terminates in an annular channel which is adapted to receive the corresponding upper or lower end of the next adjacent barrier element.

United States Patent 11 1 1111 ,804,196

Horn et al. Apr. 16, 1974 [54] NOISE ABSORBING ELEMENT IN BLOCK 1,774,065 8/1930 Muenzer 52/593 FORM 2,281,121 4/1942 Straight 181/33 R 2,933,146 4/1960 Zaldastani et a1 181/33 R X [75] Inventors: Jiirgen Horn, Holderlinweg; 3,237,714 3/1966 Surine 181/33 G UX Hans-Wilhelm Hollstein, 3,506,089 4/1970 Junger 181/33 G UX Gottingen-srone; Alexander Betker, 3,534,829 10/1970 Schneider 181/33 G UX Gottingen, all of Germany d B. W'lk' [73] Assrgnee: Schoeller & Co. KG, Gottingen, Prlmary Examiner Rlchar l mson Assistant Examiner-John F. Gonzales Germany Attorney, Agent, or FirmBurgess, Dinklage &' [22] Filed: Jan. 28, 1972 Sprung [21] Appl. No.2 221,620 [57] ABSTRACT A noise absorbing element capable of being vertically gn Application Priority- Data stacked and/or attached to vertical members includes Feb. 1,1971 Germany 2104543 a tu i h is r ctangular in cross-section which forms the front, back and side walls of the element. [52] U.S. Cl. 181/33 G, 52/145 n or m re p r i i ns n /0r spacing elements are [51] Int. Cl E04b 1/82 loc e insi e the t e and ivide the interior thereof [58] Field of Search 181/33 R, 33 G, 33 GA, into at least a front cell and a rear cell. The front cell 181/33 GB, 33 GC, 33 HE; 52/144, 145, is closed at the bottom and is filled with a sound ab- 588, 593, 609 sorbing material such as glass or rock wool. For verti- I cally stacking, the upper or lower end of the tube ter- [56] References Cited minates in an annular channel which is adapted to're- UNITED STATES PATENTS ceive the corresponding upper or lower end of the 3 001 602 9/1961 Taylor l8l/33 R adjacent barrier element 3,656,576 4/1972 Gubela SHEET 1 BF 2 PATENTEBAPR as 1974 bb oowmwwi 0000000 0000000 QOOOQOQ.

l NOISE ABSORBING ELEMENT IN BLOCK FORM BACKGROUND A form of noise barrier capable of providing suffi cient noise blocking ability for use in the outdoors has been lacking up to the present time.

SUMMARY It hasnow been found that the above-described disadvantages can be avoided if one uses for noise blocking in the outdoors a block-like noise absorbing element which includes a tube of rectangular cross-section having in some cases a constriction at the bottom, which forms the front, back and side walls of the element and contains one or more partitions and/or spacing elements dividing the interior into at least a front cell and a rear cell, the front cell being in some cases slightly offset at the top, closed at the bottom and filled with a sound absorbing material, and the upper or lower ends of the rectangular tube having channel-like annular recess which serves as stacking means for vertically stacking the elements.

DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate several embodiments of the invention and are not intended to limit same in any way.

FIG. 1a is a front elevational view partly in crossse'ction along line aa of FIG. 1b.

FIG. 1b is a cross-sectional side view taken along lin b- -b of FIG. 1c.

FIG. 1c is a top view of the element shown in FIG. 1d.

element FIG, 3d is a sectional view partly broken away.

'FIG. 4a is a front elevational view of a further embodiment of the invention.

FIG. 4b is a side cross-sectional view of the element shown in FIG. 4a.

FIG. 40 is a top view of the element shown in FIG. 4a.

FIG. 5a is a front elevational view of a further embodiment of the invention.

DESCRIPTION Such noise absorbing elements made of plastic are outstandingly suitable, owing to their easy stackability, for the erection of noise barriers and noise absorbing housings having outstanding noise abatement values.

A variety of embodiments of the block-like noise absorbing elements are described herewith.

One variant of the first described form is that the rear or middle cell is also closed at the bottom with a slight offset upwardly. The bottom of the rear or middle cell may also be tilted forward. This cell may also be filled with a heavy pourable inert particulate material such as sand and the like.

The bottom of the front cell may also be perforated or latticedf The side facing the noise, e.g., the front side, may be provided with perforations having a preferred diameter between 2 and mm. As much as 30 percent, preferably to percent, of the surface area of the front side may be perforated. The thickness of the perforated wall is to be at least 3 mm to'inhibit resonance vibration and natural vibration. The effects are additionally enhanced by superposed, open hollow cylinders.

Elements which face noise on both sides are best provided with two internal partitions, the front cell and the back cell being filled with a sound blocking material while the middle cell is empty or contains a freeflowing filler.

To improve the rigidity of the box-like structure, the longitudinal front and back wallsmay be corrugated vertically or horizontally, or they can be provided with ribs or they can be pleated.

The corners of the box are to have sufficient load bearing strength to withstand the weight of the elements stacked on top of them. Preferably they should withstand a static loading of kg/cm.

The partitions and/or spacing members serve to fix the noise blocking material in a certain position.

The spacing between the sound absorbing material and the rear wall (the depth of the middle or rear cell) of the element is to be at least mm,so as to provide reverberation space. t

For the adequate reflection of sound, a weight per unit of area of about 4 kg/m is required. The thickness of the back wall should amount to more than 4 mm. When reinforced by a lead-filled plate on a basis of plastic or rubber-elastic material, a back wall thickness of less than 3 mm will suffice. For the attachment of the lead-filled plate to the face of the back wall, the latter has mounting means which in conjunction with the floor of the box form coffer-like chambers to provide especially good reflection for the echoes.

FIG. 5b is a top view of the barrier element shown in FIG. 5a.

The lower or upper margin of the tube of rectangular cross-section, which can be constricted in some cases,

engages the channel-like groove which is sometimes provided in the upper or lower edge of the next higher or lower element, as the case may be. This channel can be provided with a sealing means, such as plastic foam.

polyethylene, sterically arranged polypropylene, polyvinyl chloride, polystyrene, especially high impact strength polystyrene, and ABS. The raw materials are used preferably in dyed and stabilized form.

To improve the mechanical characteristics of the ele ments, fillers can be added to the plastics before they are molded. Suitable fillers are, for example, glass or asbestos fibers, kaolin, talc, chalk, glass microballs and the like.

Suitable sound or noise absorbing materials for filling the front cell of the noise barrier elements are, for example, glass wool and rock wool. This material is weather-resistant, thereby avoiding corrosion. Rock wool bat sections having a weight of 5.5 to 6.5 kg/m have proven suitable. The bulk density, therefore, averages around' 100 kg/m Such bats have a thickness of 50 mm. The degree of sound absorption or, of a rock wool bat 50 mm thick and having a precise weight of 5.98 kg/m is shown in the following table for the frequencies listed:

Frequency f 01, I25 0.38 250 LOO 500 L05 1000 L00 2000 1.00 4000 1.00

The rock wool or glass wool bats are used preferably in a form prepared with hardened resins;

In addition to rock wool and glass wool, foamed plastics with open pores can also be used as sound absorbing material in the front cell, examples being polyethylene, polypropylene, polystyrene, polyurethanes, phenolic resins, epoxy adducts and other such materials. For protection against soiling, the filler material can be wrapped in a plastic foil or can be welded into a foil. Thus prevents the common impairment of its absorpition ability by dirt.

The structural components in accordance with the invention suitably have a width of 1,000 mm, a depth of 100 mm and a height of 250 or 500 mm. Any other desired dimensions are also possible, however.

The block-like noise barrier elements in accordance with the present invention are assembled to form a noise barrier by insertion and stacking between T-bars and other such vertical elements having vertical positioning or holding channels etc. To prevent rattling by wind or other pressure waves. and to improve strength, the elements can be rigidly affixed to the vertical members, e.g., by means of screws. In this case, the elements are provided with suitable apertures or bores prior to assembly. A foam can be additionally applied for insulation purposes between the back of the elements and the vertical mounting members. It is desirable to mount a roof-like cap on the top of such a noise barrier wall.

Elements such as these can also be used indoors as partition walls or as wall coverings.

What is claimed is:

1. Noise barrier element comprising a tube made of a polymeric material of rectangular cross-section forming the front, back and side walls of the element, said tube containing one or more spacing means which divide the interior thereof into at least a front cell and a rear cell, the front cell being closed at the bottom and filled with a sound absorbing material, said rectangular tube having stacking means for vertically stacking a plurality of said elements consisting of an annular channel formed by an end of said rectangular tube and an annular margin formed by the other end of said rectangular tube, said annular channel being adapted to receive the corresponding annular margin of the next adjacent barrier element and said annular margin being adapted to fit into the annular channel of the next adjacent barrier element.

2. Noise barrier element of claim 1 wherein the rear cell is also closed at the bottom and slightly offset upwardly.

3. Noise barrier element of claim 1 wherein the floor of the rear cell is tilted forwardly.

4. Noise barrier element of claim 1 wherein the floor of the front cell is constructed in the form of a perforated floor. a

5. Noise barrier element of claim 1 the front wall is provided with perforations.

6. Noise barrier element of claim 1 whereina leadfilled plate is disposed in front of the rear wall.

7. Noise barrier element of claim 1 wherein at least one of the front and rear walls are corrugated.

8. Noise barrier element of claim 1 wherein the rear cell is closed at the bottom and filled with an inert particulate material.

9. Noise barrier element of claim 1 wherein said tube contains two partition walls which divide the interior of said element into a front cell and a rear cell separated by a middle cell, said front cell and said rear cell each being filled with a sound absorbing material.

10. Noise barrier element of claim 1 wherein the rear cell is filled with a heavy pourable inert particulate material.

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1. Noise barrier element comprising a tube made of a polymeric material of rectangular cross-section forming the front, back and side walls of the element, said tube containing one or more spacing means which divide the interior thereof into at least a front cell and a rear cell, the front cell being closed at the bottom and filled with a sound absorbing material, said rectangular tube having stacking means for vertically stacking a plurality of said elements consisting of an annular channel formed by an end of said rectangular tube and an annular margin formed by the other end of said rectangular tube, said annular channel being adapted to receive the corresponding annular margin of the next adjacent barrier element and said annular margin being adapted to fit into the annular channel of the next adjacent barrier element.
 2. Noise barrier element of claim 1 wherein the rear cell is also closed at the bottom and slightly offset upwardly.
 3. Noise barrier element of claim 1 wherein the floor of the rear cell is tilted forwardly.
 4. Noise barrier element of claim 1 wherein the floor of the front cell is constructed in the form of a perforated floor.
 5. Noise barrier element of claim 1 the front wall is provided with perforations.
 6. Noise barrier element of claim 1 wherein a lead-filled plate is disposed in front of the rear wall.
 7. Noise barrier element of claim 1 wherein at least one of the front and rear walls are corRugated.
 8. Noise barrier element of claim 1 wherein the rear cell is closed at the bottom and filled with an inert particulate material.
 9. Noise barrier element of claim 1 wherein said tube contains two partition walls which divide the interior of said element into a front cell and a rear cell separated by a middle cell, said front cell and said rear cell each being filled with a sound absorbing material.
 10. Noise barrier element of claim 1 wherein the rear cell is filled with a heavy pourable inert particulate material. 